<template>
  <div class="msite">
    <!--首页头部-->
    <HeaderTop :title="address.name">
       <router-link class="header_search" slot="left" to="/search">
      <i class="iconfont icon-sousuo"></i>
      </router-link>
      <router-link class="header_login" slot="right" :to="userInfo._id?'/userInfo':'/login'">
        <span class="header_login_text" v-if="!userInfo._id">登录|注册</span>
        <span class="header_login_text" v-else>
          <i class="iconfont icon-wodezhanghao"></i>
        </span>
      </router-link>
    </HeaderTop>
    <!--首页导航-->
    <nav class="msite_nav">
      <div class="swiper-container" v-if="categorys.length">
        <div class="swiper-wrapper">
          <div class="swiper-slide" v-for="(categorys, index) in categorysArr" :key="index">
            <a href="javascript:" class="link_to_food" v-for="(category, index) in categorys" :key="index">
              <div class="food_container">
                <img :src="baseImageUrl + category.image_url">
              </div>
              <span>{{ category.title }}</span>
            </a>
          </div>
        </div>
        <!-- Add Pagination -->
        <div class="swiper-pagination"></div>
      </div>
      <img src="./images/msite_back.svg" alt="back" v-else>
    </nav>
    <!--首页附近商家-->
    <div class="msite_shop_list">
      <div class="shop_header">
        <i class="iconfont icon-xuanxiang"></i>
        <span class="shop_header_title">附近商家</span>
      </div>
      <ShopList/>
    </div>
  </div>
</template>

<script>
import {mapState} from 'vuex'
import Swiper from 'swiper'
import 'swiper/dist/css/swiper.min.css'

import HeaderTop from '../../components/HeaderTop/HeaderTop'
import ShopList from '../../components/ShopList/ShopList'

export default {
  data () {
    return {
      baseImageUrl: 'https://fuss10.elemecdn.com'
    }
  },
  mounted () {
    this.$store.dispatch('getCategorys')
    this.$store.dispatch('getShops')
  },
  computed: {
    ...mapState(['address', 'categorys', 'userInfo']),
    // 计算属性 根据categorys一维数组生成一个二维数组
    /*
    * 小数组中的元素个数最大是8
    * */
    categorysArr () {
      const {categorys} = this
      // 准备空的 二维数组
      const arr = []
      // 准备一个小数组（最大长度为8）
      let minArr = []

      // 遍历 categorys
      categorys.forEach(c => {
        // 如果当前小数组已经满了，创建一个新的
        if (minArr.length === 8) {
          minArr = []
        }
        // 如果minArr是空的，将小数组保存到大数组中
        if (minArr.length === 0) {
          arr.push(minArr)
        }
        // 将当前分类保存到小数组中
        minArr.push(c)
      })

      return arr
    }
  },
  watch: {
    categorys () {
      // 界面更新就立即创建swiper组件
      this.$nextTick(() => { // 一旦完成界面更新 立即调用
        /* eslint-disable no-new */
        // 创建一个是wiper实例对象
        new Swiper('.swiper-container', {
          loop: true, // 循环轮播
          // 如果需要分页器
          pagination: {
            el: '.swiper-pagination'
          }
        })
      })
    }
  },
  components: {
    HeaderTop,
    ShopList
  }
}
</script>

<style lang="stylus" rel="stylesheet/stylus">
  @import "../../common/stylus/mixins.styl"
  .msite  //首页
    width 100%
    .msite_nav
      bottom-border-1px(#e4e4e4)
      margin-top 45px
      height 200px
      background #fff
      .swiper-container
        width 100%
        height 100%
        .swiper-wrapper
          width 100%
          height 100%
          .swiper-slide
            display flex
            justify-content center
            align-items flex-start
            flex-wrap wrap
            .link_to_food
              width 25%
              .food_container
                display block
                width 100%
                text-align center
                padding-bottom 10px
                font-size 0
                img
                  display inline-block
                  width 50px
                  height 50px
              span
                display block
                width 100%
                text-align center
                font-size 13px
                color #666
        .swiper-pagination
          >span.swiper-pagination-bullet-active
            background $blue
</style>
